The Tor Browser: security/nss/lib/freebl/ecl/ecl

security/nss/lib/freebl/ecl/ecl_mult.c@6474c204b198 (annotated)

security/nss/lib/freebl/ecl/ecl_mult.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "mpi.h"
 #include "mplogic.h"
 #include "ecl.h"
 #include "ecl-priv.h"
 #include <stdlib.h>
 /* Elliptic curve scalar-point multiplication. Computes R(x, y) = k * P(x,
  * y).  If x, y = NULL, then P is assumed to be the generator (base point)
  * of the group of points on the elliptic curve. Input and output values
  * are assumed to be NOT field-encoded. */
 mp_err
 ECPoint_mul(const ECGroup *group, const mp_int *k, const mp_int *px,
 			const mp_int *py, mp_int *rx, mp_int *ry)
 {
 	mp_err res = MP_OKAY;
 	mp_int kt;
 	ARGCHK((k != NULL) && (group != NULL), MP_BADARG);
 	MP_DIGITS(&kt) = 0;
 	/* want scalar to be less than or equal to group order */
 	if (mp_cmp(k, &group->order) > 0) {
 		MP_CHECKOK(mp_init(&kt));
 		MP_CHECKOK(mp_mod(k, &group->order, &kt));
 	} else {
 		MP_SIGN(&kt) = MP_ZPOS;
 		MP_USED(&kt) = MP_USED(k);
 		MP_ALLOC(&kt) = MP_ALLOC(k);
 		MP_DIGITS(&kt) = MP_DIGITS(k);
 	}
 	if ((px == NULL) || (py == NULL)) {
 		if (group->base_point_mul) {
 			MP_CHECKOK(group->base_point_mul(&kt, rx, ry, group));
 		} else {
 			MP_CHECKOK(group->
 					   point_mul(&kt, &group->genx, &group->geny, rx, ry,
 								 group));
 		}
 	} else {
 		if (group->meth->field_enc) {
 			MP_CHECKOK(group->meth->field_enc(px, rx, group->meth));
 			MP_CHECKOK(group->meth->field_enc(py, ry, group->meth));
 			MP_CHECKOK(group->point_mul(&kt, rx, ry, rx, ry, group));
 		} else {
 			MP_CHECKOK(group->point_mul(&kt, px, py, rx, ry, group));
 		}
 	}
 	if (group->meth->field_dec) {
 		MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth));
 		MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth));
 	}
   CLEANUP:
 	if (MP_DIGITS(&kt) != MP_DIGITS(k)) {
 		mp_clear(&kt);
 	}
 	return res;
 }
 /* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G +
  * k2 * P(x, y), where G is the generator (base point) of the group of
  * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL.
  * Input and output values are assumed to be NOT field-encoded. */
 mp_err
 ec_pts_mul_basic(const mp_int *k1, const mp_int *k2, const mp_int *px,
 				 const mp_int *py, mp_int *rx, mp_int *ry,
 				 const ECGroup *group)
 {
 	mp_err res = MP_OKAY;
 	mp_int sx, sy;
 	ARGCHK(group != NULL, MP_BADARG);
 	ARGCHK(!((k1 == NULL)
 			 && ((k2 == NULL) || (px == NULL)
 				 || (py == NULL))), MP_BADARG);
 	/* if some arguments are not defined used ECPoint_mul */
 	if (k1 == NULL) {
 		return ECPoint_mul(group, k2, px, py, rx, ry);
 	} else if ((k2 == NULL) || (px == NULL) || (py == NULL)) {
 		return ECPoint_mul(group, k1, NULL, NULL, rx, ry);
 	}
 	MP_DIGITS(&sx) = 0;
 	MP_DIGITS(&sy) = 0;
 	MP_CHECKOK(mp_init(&sx));
 	MP_CHECKOK(mp_init(&sy));
 	MP_CHECKOK(ECPoint_mul(group, k1, NULL, NULL, &sx, &sy));
 	MP_CHECKOK(ECPoint_mul(group, k2, px, py, rx, ry));
 	if (group->meth->field_enc) {
 		MP_CHECKOK(group->meth->field_enc(&sx, &sx, group->meth));
 		MP_CHECKOK(group->meth->field_enc(&sy, &sy, group->meth));
 		MP_CHECKOK(group->meth->field_enc(rx, rx, group->meth));
 		MP_CHECKOK(group->meth->field_enc(ry, ry, group->meth));
 	}
 	MP_CHECKOK(group->point_add(&sx, &sy, rx, ry, rx, ry, group));
 	if (group->meth->field_dec) {
 		MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth));
 		MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth));
 	}
   CLEANUP:
 	mp_clear(&sx);
 	mp_clear(&sy);
 	return res;
 }
 /* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G +
  * k2 * P(x, y), where G is the generator (base point) of the group of
  * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL.
  * Input and output values are assumed to be NOT field-encoded. Uses
  * algorithm 15 (simultaneous multiple point multiplication) from Brown,
  * Hankerson, Lopez, Menezes. Software Implementation of the NIST
  * Elliptic Curves over Prime Fields. */
 mp_err
 ec_pts_mul_simul_w2(const mp_int *k1, const mp_int *k2, const mp_int *px,
 					const mp_int *py, mp_int *rx, mp_int *ry,
 					const ECGroup *group)
 {
 	mp_err res = MP_OKAY;
 	mp_int precomp[4][4][2];
 	const mp_int *a, *b;
 	int i, j;
 	int ai, bi, d;
 	ARGCHK(group != NULL, MP_BADARG);
 	ARGCHK(!((k1 == NULL)
 			 && ((k2 == NULL) || (px == NULL)
 				 || (py == NULL))), MP_BADARG);
 	/* if some arguments are not defined used ECPoint_mul */
 	if (k1 == NULL) {
 		return ECPoint_mul(group, k2, px, py, rx, ry);
 	} else if ((k2 == NULL) || (px == NULL) || (py == NULL)) {
 		return ECPoint_mul(group, k1, NULL, NULL, rx, ry);
 	}
 	/* initialize precomputation table */
 	for (i = 0; i < 4; i++) {
 		for (j = 0; j < 4; j++) {
 			MP_DIGITS(&precomp[i][j][0]) = 0;
 			MP_DIGITS(&precomp[i][j][1]) = 0;
 		}
 	}
 	for (i = 0; i < 4; i++) {
 		for (j = 0; j < 4; j++) {
 			 MP_CHECKOK( mp_init_size(&precomp[i][j][0],
 						 ECL_MAX_FIELD_SIZE_DIGITS) );
 			 MP_CHECKOK( mp_init_size(&precomp[i][j][1],
 						 ECL_MAX_FIELD_SIZE_DIGITS) );
 		}
 	}
 	/* fill precomputation table */
 	/* assign {k1, k2} = {a, b} such that len(a) >= len(b) */
 	if (mpl_significant_bits(k1) < mpl_significant_bits(k2)) {
 		a = k2;
 		b = k1;
 		if (group->meth->field_enc) {
 			MP_CHECKOK(group->meth->
 					   field_enc(px, &precomp[1][0][0], group->meth));
 			MP_CHECKOK(group->meth->
 					   field_enc(py, &precomp[1][0][1], group->meth));
 		} else {
 			MP_CHECKOK(mp_copy(px, &precomp[1][0][0]));
 			MP_CHECKOK(mp_copy(py, &precomp[1][0][1]));
 		}
 		MP_CHECKOK(mp_copy(&group->genx, &precomp[0][1][0]));
 		MP_CHECKOK(mp_copy(&group->geny, &precomp[0][1][1]));
 	} else {
 		a = k1;
 		b = k2;
 		MP_CHECKOK(mp_copy(&group->genx, &precomp[1][0][0]));
 		MP_CHECKOK(mp_copy(&group->geny, &precomp[1][0][1]));
 		if (group->meth->field_enc) {
 			MP_CHECKOK(group->meth->
 					   field_enc(px, &precomp[0][1][0], group->meth));
 			MP_CHECKOK(group->meth->
 					   field_enc(py, &precomp[0][1][1], group->meth));
 		} else {
 			MP_CHECKOK(mp_copy(px, &precomp[0][1][0]));
 			MP_CHECKOK(mp_copy(py, &precomp[0][1][1]));
 		}
 	}
 	/* precompute [*][0][*] */
 	mp_zero(&precomp[0][0][0]);
 	mp_zero(&precomp[0][0][1]);
 	MP_CHECKOK(group->
 			   point_dbl(&precomp[1][0][0], &precomp[1][0][1],
 						 &precomp[2][0][0], &precomp[2][0][1], group));
 	MP_CHECKOK(group->
 			   point_add(&precomp[1][0][0], &precomp[1][0][1],
 						 &precomp[2][0][0], &precomp[2][0][1],
 						 &precomp[3][0][0], &precomp[3][0][1], group));
 	/* precompute [*][1][*] */
 	for (i = 1; i < 4; i++) {
 		MP_CHECKOK(group->
 				   point_add(&precomp[0][1][0], &precomp[0][1][1],
 							 &precomp[i][0][0], &precomp[i][0][1],
 							 &precomp[i][1][0], &precomp[i][1][1], group));
 	}
 	/* precompute [*][2][*] */
 	MP_CHECKOK(group->
 			   point_dbl(&precomp[0][1][0], &precomp[0][1][1],
 						 &precomp[0][2][0], &precomp[0][2][1], group));
 	for (i = 1; i < 4; i++) {
 		MP_CHECKOK(group->
 				   point_add(&precomp[0][2][0], &precomp[0][2][1],
 							 &precomp[i][0][0], &precomp[i][0][1],
 							 &precomp[i][2][0], &precomp[i][2][1], group));
 	}
 	/* precompute [*][3][*] */
 	MP_CHECKOK(group->
 			   point_add(&precomp[0][1][0], &precomp[0][1][1],
 						 &precomp[0][2][0], &precomp[0][2][1],
 						 &precomp[0][3][0], &precomp[0][3][1], group));
 	for (i = 1; i < 4; i++) {
 		MP_CHECKOK(group->
 				   point_add(&precomp[0][3][0], &precomp[0][3][1],
 							 &precomp[i][0][0], &precomp[i][0][1],
 							 &precomp[i][3][0], &precomp[i][3][1], group));
 	}
 	d = (mpl_significant_bits(a) + 1) / 2;
 	/* R = inf */
 	mp_zero(rx);
 	mp_zero(ry);
 	for (i = d - 1; i >= 0; i--) {
 		ai = MP_GET_BIT(a, 2 * i + 1);
 		ai <<= 1;
 		ai |= MP_GET_BIT(a, 2 * i);
 		bi = MP_GET_BIT(b, 2 * i + 1);
 		bi <<= 1;
 		bi |= MP_GET_BIT(b, 2 * i);
 		/* R = 2^2 * R */
 		MP_CHECKOK(group->point_dbl(rx, ry, rx, ry, group));
 		MP_CHECKOK(group->point_dbl(rx, ry, rx, ry, group));
 		/* R = R + (ai * A + bi * B) */
 		MP_CHECKOK(group->
 				   point_add(rx, ry, &precomp[ai][bi][0],
 							 &precomp[ai][bi][1], rx, ry, group));
 	}
 	if (group->meth->field_dec) {
 		MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth));
 		MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth));
 	}
   CLEANUP:
 	for (i = 0; i < 4; i++) {
 		for (j = 0; j < 4; j++) {
 			mp_clear(&precomp[i][j][0]);
 			mp_clear(&precomp[i][j][1]);
 		}
 	}
 	return res;
 }
 /* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G +
  * k2 * P(x, y), where G is the generator (base point) of the group of
  * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL.
  * Input and output values are assumed to be NOT field-encoded. */
 mp_err
 ECPoints_mul(const ECGroup *group, const mp_int *k1, const mp_int *k2,
 			 const mp_int *px, const mp_int *py, mp_int *rx, mp_int *ry)
 {
 	mp_err res = MP_OKAY;
 	mp_int k1t, k2t;
 	const mp_int *k1p, *k2p;
 	MP_DIGITS(&k1t) = 0;
 	MP_DIGITS(&k2t) = 0;
 	ARGCHK(group != NULL, MP_BADARG);
 	/* want scalar to be less than or equal to group order */
 	if (k1 != NULL) {
 		if (mp_cmp(k1, &group->order) >= 0) {
 			MP_CHECKOK(mp_init(&k1t));
 			MP_CHECKOK(mp_mod(k1, &group->order, &k1t));
 			k1p = &k1t;
 		} else {
 			k1p = k1;
 		}
 	} else {
 		k1p = k1;
 	}
 	if (k2 != NULL) {
 		if (mp_cmp(k2, &group->order) >= 0) {
 			MP_CHECKOK(mp_init(&k2t));
 			MP_CHECKOK(mp_mod(k2, &group->order, &k2t));
 			k2p = &k2t;
 		} else {
 			k2p = k2;
 		}
 	} else {
 		k2p = k2;
 	}
 	/* if points_mul is defined, then use it */
 	if (group->points_mul) {
 		res = group->points_mul(k1p, k2p, px, py, rx, ry, group);
 	} else {
 		res = ec_pts_mul_simul_w2(k1p, k2p, px, py, rx, ry, group);
 	}
   CLEANUP:
 	mp_clear(&k1t);
 	mp_clear(&k2t);
 	return res;
 }

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security/nss/lib/freebl/ecl/ecl_mult.c@6474c204b198 (annotated)

security/nss/lib/freebl/ecl/ecl_mult.c